JP3184247B2 - Intake device for engine with mechanical supercharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine having a plurality of cylinders in which intake air is supercharged by a mechanical supercharger driven by an engine output. The present invention relates to an intake device for a mechanical supercharged engine including a passage portion.

[0002]

2. Description of the Related Art In the field of an engine mounted on a vehicle, a mechanical supercharger driven and driven by transmission of rotation of a crankshaft to an intake passage connected to an engine body. And increasing the intake air filling rate in each of a plurality of cylinders provided in the engine body by the supercharging operation of the mechanical supercharger, thereby obtaining an engine with high output. It has been known. And, in an engine provided with a mechanical supercharger that is driven by transmission of rotation of a crankshaft,
When operating under a relatively low load, the mechanical supercharger is deactivated, and when operating under a relatively high load, the mechanical supercharger is activated. Activated, whereby when operating under relatively high load, each cylinder is supercharged, the intake charge is increased and the engine output is increased. There are many.

[0003] In such an engine with a mechanical supercharger in which high output is achieved by providing a mechanical supercharger,
There is a problem that the temperature inside each cylinder rises significantly when the mechanical supercharger operates, and as a result, a knocking phenomenon easily occurs. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. H2-119621, in an engine with a mechanical supercharger, each of the cylinders is utilized by utilizing intake air supercharged into each cylinder by the mechanical supercharger. In order to suppress the temperature rise in each cylinder by performing scavenging of the post-combustion residual gas in the cylinder, the intake air provided for each cylinder when in the high rotation operation state where the knocking phenomenon easily occurs. It has been proposed that the overlap period in which both the valve and the exhaust valve are opened is set to be relatively long so that scavenging for each cylinder is performed satisfactorily.

Further, as an engine mounted on a vehicle,
Each of a plurality of cylinders provided in the engine main body is connected to a common intake passage portion through a plurality of, for example, two individual intake passages, and openings of each of the plurality of individual intake passages corresponding to each cylinder with respect to each cylinder. Are controlled to be opened and closed by individually provided intake valves, whereby
There is also known a multi-valve engine in which the intake area in each cylinder is enlarged to improve the intake charging efficiency. As one of such multi-valve engines, for example,
As disclosed in Japanese Patent Application Laid-Open No. 61-11455, two individual intake passages are provided for one cylinder, and when the engine is in a low-speed operation state, one of the two individual intake passages is provided. Supply of intake air to the cylinder is performed through only one of the two individual intake passages, and when the engine is in a high-speed operation state, supply of intake air to the cylinder is performed through one of the two individual intake passages and the other. In addition, one in which a fuel injection valve is provided in one of two individual intake passages has been proposed.

In such a multi-valve engine, a mechanical supercharger is provided in a common intake passage portion thereof.
Even in the case of a multi-valve engine with a mechanical supercharger, there is a problem that the knocking phenomenon easily occurs due to a rise in the temperature in each cylinder when the mechanical supercharger operates, and On the other hand, by setting a relatively long overlap period in which both the intake valve and the exhaust valve provided for each cylinder are opened, the scavenging for each cylinder is performed satisfactorily. The following measures are taken. In such a multi-valve engine with a mechanical supercharger, in a state where intake air is supplied to each cylinder through a plurality of individual intake passages provided for the cylinder,
Usually, a plurality of intake valves provided corresponding to each cylinder are simultaneously in an open state in which an opening to each of the plurality of individual intake passages is opened, and each of the plurality of individual intake passages is opened. The valve is in a closed state in which the opening to the cylinder is closed.

[0006]

However, as described above, in the engine with a mechanical supercharger, the scavenging of the residual gas after combustion in each cylinder is effectively performed to reduce the occurrence of the knocking phenomenon in each cylinder. To avoid
When the overlap period in which both the intake valve and the exhaust valve provided for each cylinder are opened is set to be relatively long, the fuel injection valve provided for each cylinder is provided. The fuel supplied to each cylinder is blown from the intake valve side to the exhaust valve side,
The inconvenience that the amount of fuel blown into the exhaust passage is increased is posed.

In view of the above, the present invention provides an engine with a mechanical supercharger including an intake passage in which a mechanical supercharger is provided, and is provided in the engine with a mechanical supercharger. The present invention provides an engine intake device with a mechanical supercharger, which can achieve both suppression of occurrence of a knocking phenomenon in each of a plurality of cylinders and reduction of the amount of fuel blown to the exhaust passage side. The purpose is to:

[0008]

In order to achieve the above object, an intake device for an engine with a mechanical supercharger according to the present invention comprises: a common intake passage in which a mechanical supercharger is disposed; Includes a first and a second individual intake passage, each of which connects a corresponding cylinder to a common intake passage portion, and the first individual intake passage has a first And a valve opening state for opening / closing an opening of the first individual intake passage for the cylinder provided with fuel supply means for performing a fuel supply operation to a cylinder connected to the first individual intake passage. And a second intake valve for selectively opening and closing a valve for opening and closing an opening of the second individual intake passage to the cylinder. And the driving of the first and second intake valves There, by Moto the engine body is in a predetermined operating condition, when the intake stroke for each cylinder, a time when the first intake valve starts to transition from the closed state to the open state, the second intake valve Is later than the time when the transition from the valve closed state to the valve open state is started,
Then the first intake valve and the time to complete the transition from the open state to the closed state, the second intake valve is what slower than the time to complete the transition to the closed state from the open state and forms the intake valve Drive
Control means, wherein the fuel supply means includes a first intake valve and a second intake valve.
Exhaust connected to a cylinder corresponding to one individual intake passage
During the overlap period when both the valve and the valve are open
And supply fuel to the cylinder.
It is composed.

[0009]

In the intake system for a mechanically-charged engine according to the present invention having the above-described structure, first and second individual intake passages for connecting each cylinder to a common intake passage are provided. And only the first individual intake passage among them, with respect to the cylinder of the first individual intake passage.
Opening and closing the valve to selectively open and close the opening.
The first intake valve to be taken and the exhaust valve corresponding to the cylinder are
A fuel supply means for performing a fuel supply operation to the cylinder during the overlap period in which both are in the valve open state is provided, and when the engine body is in a predetermined operation state, for example, in a high load operation state. In the intake stroke of each cylinder, the time when the first intake valve starts to shift from the closed state to the open state is determined to be in the open state to open and close the opening of the second individual intake passage to the cylinder. The second intake valve, which selectively takes the closed state, is set to be later than the time when the transition from the closed state to the open state is started, and then the first intake valve is closed from the open state. The time point at which the transition to the state is completed is later than the time point at which the second intake valve completes the transition from the open state to the closed state.

Thus, for example, when the engine body is in a high-load operation state, the valve is opened and closed to open and close the opening of the cylinder of the second individual intake passage in which the fuel supply means is not provided. The overlap period in which the second intake valve selectively taking the valve state and the exhaust valve corresponding to the cylinder are both in the open state is relatively long, and the first in which the fuel supply means is disposed. The first intake valve selectively opening and closing to open and close the opening of the individual intake passage for the cylinder and the exhaust valve corresponding to the cylinder are both opened. period Ru is relatively short. As described above, since the overlap period in which the second intake valve and the exhaust valve are both opened is relatively long, the scavenging of the cylinder is performed well, and the occurrence of the knocking phenomenon is suppressed. And the fuel arranged in the first individual intake passage.
Fuel is supplied to the cylinder by the fuel supply means
The overlap period in which the first intake valve and the exhaust valve are both opened is relatively short, so that the fuel is supplied to the cylinder by the fuel supply means disposed in the first individual intake passage. The amount of fuel blown out toward the exhaust passage, which is caused by the flow of fuel flowing from the first intake valve side to the exhaust valve side, is suppressed.

[0011]

1 and 2 show an example of an intake device of a mechanical supercharged engine according to the present invention, together with an in-line four-cylinder engine to which it is applied.

In FIGS. 1 and 2, an engine body 1 is shown.
Are constituted by a cylinder block 2, an oil pan arranged below the cylinder block 2, a cylinder head 4 arranged above the cylinder block 2, and a head cover 5 arranged above the cylinder head 4. It has been. Inside the cylinder block 2, the piston 1
The cylinder head 4 has four cylinders 6 arranged in series, and the cylinder head 4 has an intake manifold 11
And the upstream end of the exhaust manifold 13 are connected.

As shown in FIGS. 2 and 3, on the upper part of each of the four cylinders 6, the respective downstream ends of a pair of intake ports 7 and 8 formed in the cylinder head 4, and A pair of ends of a branch portion of the branch exhaust port 9 formed in the cylinder head 4 is opened. The upstream ends of the pair of intake ports 7 and 8 are connected to individual passages 35 and 36 in the intake manifold 11, respectively. A first individual intake passage 39 is formed by the intake ports 7 and the individual passages 35. The port 8 and the individual passage 36 form a second individual intake passage 40, and the first and second individual intake passages 3
9 and 40 form a cylinder-specific intake passage. The upstream end of the intake manifold 11 is connected to a surge tank 33 that forms a downstream portion of the common intake passage 10, and therefore, each of the four cylinders 6
A downstream portion of the common intake passage portion 10 is formed through a first individual intake passage 39 composed of the intake ports 7 and the individual passages 35 arranged in parallel and a second individual intake passage 40 composed of the intake ports 8 and the individual passages 36. Surge tank 33
It will be connected to.

At the downstream ends of the pair of intake ports 7 and 8, intake valves 20 and 21 are disposed, respectively. The intake valve 20 opens and closes an opening to the cylinder 6 at the downstream end of the intake port 7. Opening state and closing state to be selectively taken, and the intake valve 21 is connected to the intake port 8.
A valve opening state and a valve closing state for opening and closing an opening to the cylinder 6 at the downstream end of the valve are selectively taken. Then, as clearly shown in FIG. 2 and FIG.
A fuel injection valve 38 is disposed in the individual passage 35 of the intake manifold 11 that forms the individual intake passage 39 of FIG.

On the other hand, as shown in FIGS. 2 and 3, the end of the gathering portion of the branch exhaust port 9 is connected to the exhaust manifold 1.
3 is connected to the individual passage 14 in the exhaust manifold 13, and the common passage 15 in the exhaust manifold 13 is connected to the common exhaust passage 1.
6. A pair of exhaust valves 23 are disposed at a pair of ends of a branch portion of the branch exhaust port 9, and each of the exhaust valves 23 opens and closes an opening for the cylinder 6 at a branch portion of the branch exhaust port 9. The valve opening state and the valve closing state are selectively selected.

An air cleaner 25, an air flow sensor 26, a throttle valve 27 with a throttle opening sensor 27A, and a crankshaft 28 disposed in the engine body 1 are arranged in the common intake passage section 10 in this order from the upstream side (FIG. 2). Of rotation is selectively transmitted via a belt 29 and an electromagnetic clutch 30 to operate the rechargeable mechanical supercharger 31, an intercooler 32 for cooling intake air in the common intake passage 10, and a surge A tank 33 is provided. Electromagnetic clutch 30 provided in mechanical supercharger 31
Are shut off when the engine body 1 is in a relatively low speed and low load operation state, and are connected when the engine body 1 is in a relatively high speed or high load operation state. Accordingly, when the engine main body 1 is in a relatively low speed and low load operation state, the mechanical supercharger 31 is not operated, the rotation of the crankshaft 28 is not transmitted, and the mechanical supercharger 31 is not operated. When the vehicle is in a high-speed or high-load operation state, the rotation of the crankshaft 28 is transmitted, and the cylinder 6 is in a supercharging operation state in which the intake air filling rate is increased.

The portion between the throttle valve 27 and the mechanical supercharger 31 in the common intake passage 10 and the surge tank 3
3 is connected by an intake bypass 41, and the intake bypass 41 is provided with a diaphragm-type intake bypass control valve 43 driven by a solenoid valve 42. In response to the control signal SS supplied to the solenoid valve 42, when the engine body 1 is in a relatively low speed and low load operation state, the intake pressure obtained in the surge tank 33 is supplied to the intake bypass control valve 43 through the intake bypass 41. When the engine body 1 is in a relatively high speed or high load operation state, the intake pressure obtained in the surge tank 33 is applied to the pressure chamber of the intake bypass control valve 43 when the engine body 1 is in a relatively high speed or high load operation state. It is assumed that the operating state is not guided. Thereby, the intake bypass control valve 43 opens the intake bypass 41 when the engine body 1 is in a relatively low speed and low load operation state and the mechanical supercharger 31 is in a non-operation state. In addition, the intake air through the throttle valve 27 in the common intake passage 10 flows directly into the surge tank 33 through the intake bypass 41, and the passage resistance to the intake air is reduced.

When the engine body 1 is in a relatively high-speed or high-load operating state and the mechanical supercharger 31 is in a supercharging operation state, the intake bypass control valve 43 controls the mechanical bypass in the common intake passage section 10. The amount of recirculation in the intake bypass 41 is controlled so that the intake pressure in a portion downstream of the supercharger 31 is a predetermined value that is equal to or lower than a sufficiently high value set in advance. Part 10
Is supplied to the supercharger by the mechanical supercharger 31, and a relatively high intake pressure is obtained in the surge tank 33. Then, under such circumstances, if the intake pressure in the portion of the common intake passage portion 10 downstream of the mechanical supercharger 31 exceeds a sufficiently high value set in advance, the solenoid valve 42
The intake pressure obtained in the surge tank 33 is the intake bypass 41
Through the pressure chamber of the intake bypass control valve 43,
The intake bypass control valve 43 assumes a state in which the intake bypass 41 is opened, whereby the intake pressure obtained in the surge tank 33 is reduced through the intake bypass 41 and the common intake passage portion 10 Is adjusted so that the intake pressure at a portion downstream of the mechanical supercharger 31 is equal to or less than a preset sufficiently high value,
A situation in which the intake pressure in the common intake passage section 10 becomes excessively large and adversely affects each section is avoided.

As described above, in the engine body 1, the first and second individual intake passages 39 correspond to the respective cylinders 6.
And 40 are provided to increase the intake area,
In particular, when in a relatively high speed or high load operation state,
The intake air that is pressurized by the mechanical supercharger 31 and cooled by the intercooler 32 is supplied to each cylinder 6 through the first and second individual intake passages 39 and 40. The intake filling rate and the combustibility are improved, and high output is achieved.

Intake valves 20 and 21 for opening and closing the openings for the cylinder 6 at the downstream ends of a pair of intake ports 7 and 8 provided for each cylinder 6, respectively, and also provided for each cylinder 6. Branch exhaust port 9
A pair of exhaust valves 23 for opening and closing the opening to the cylinder 6 at the branch portion of the cylinder head 4 is provided with a variable valve timing mechanism 45 constituting a valve operating mechanism disposed in the cylinder head 4.
Each operation is controlled by
The engine body 1 is provided with a hydraulic circuit 49 for supplying an operating hydraulic pressure to the variable valve timing mechanism 45 and a control block 50 for controlling the hydraulic circuit 49.

The variable valve timing mechanism 45 is constructed, for example, as shown in FIG. 4, and the rotation of the crankshaft 28 is transmitted to the gears 47 and 48 via the cogged belt 46, and the gears 47 and 48 are assembled respectively. The intake-side camshaft 51 and the exhaust-side camshaft 52 are driven. An annular spacer 5 that is bolted to one end surface of the intake camshaft 51 and protrudes in the direction in which the intake camshaft 51 extends.
3 and a cover member 54 that covers the spacer 53
And is assembled. The cover member 54 is a first cylindrical member 5 fitted to one end of the intake side camshaft 51.
4A, the second tubular member 54B, which is bolted to the first tubular member 54A and the gear 47 and forms a space 55 between the first tubular member 54A and the outer peripheral surface of the spacer 53, and the spacer 53 A gap 57 communicating with the oil passage 56 penetrating through the intake camshaft 51 and the spacer 53 is formed therebetween, and is formed by a disc-shaped member 54C that covers the protruding end surface of the spacer 53. In the space 55 formed between the second cylindrical member 54B and the spacer 53, an annular piston member 59 urged toward the disk member 54C by the coil spring 58 is disposed. .

The piston member 59 is connected to the first cylindrical member 54.
A first annular body 59A located on the A side and a disc-shaped member 54
The first annular member 5 is located on the C side by a plurality of pins 59B.
9A connected to the second annular body 59C, the outer peripheral surface portion is helically spline-engaged with the inner peripheral surface portion of the second tubular member 54B, and the inner peripheral surface portion is the outer periphery of the spacer 53. The helical spline is engaged with the surface. Piston member 59 and second cylindrical member 5
4B and helical spline engagement with the piston member 59
The twisting direction is opposite to the helical spline engagement between the spacer and the spacer 53. Such a piston member 59
When the operating oil pressure from the hydraulic circuit unit 49 is not applied, the urging force of the coil spring 58 is maintained at the position on the disc-shaped member 54C side, and the operating oil pressure from the hydraulic circuit unit 49 is When acting on the second annular body 59C through the gap 57 formed between the disc-shaped member 54C and the spacer 53 from the coil spring 5, the coil spring 5
8 is moved in a direction along the intake camshaft 51 against the urging force of the camshaft 8.

The intake-side camshaft 51 is formed with four pairs of intake-side cam portions 60 and 61. The pair of intake-side cam portions 60 and 61 are provided for each cylinder 6 respectively. Valves 20 and 21 for opening and closing the openings for the cylinder 6 at the downstream ends of the intake ports 7 and 8, respectively.
Is to be driven. On the other hand, the exhaust side camshaft 52
Also, four pairs of exhaust-side cam portions 63 are formed, and the pair of exhaust-side cam portions 63 are respectively provided with respect to the cylinder 6 at the branch portion of the branch exhaust port 9 provided for each cylinder 6. It drives a pair of exhaust valves 23 that open and close the openings, respectively. The intake cams 60 and 61 control the opening and closing timing of the intake valve 20 that opens and closes the opening to the cylinder 6 at the downstream end of the intake port 7 connected to the individual passage 35 in which the fuel injection valve 38 is provided. Individual passage 36 without fuel injection valve 38
The intake port 8 connected to the intake port 8 is arranged with a mutual rotational phase difference that is delayed from the opening and closing timing of the intake valve 21 that opens and closes the opening to the cylinder 6 at the downstream end. Further, the pair of exhaust-side cam portions 63 causes the pair of exhaust valves 23 to simultaneously open and close.

Under these circumstances, the intake valve 21 has the valve opening displacement Ds on the vertical axis and the time t on the horizontal axis in accordance with the rotation of the intake cam portion 61 accompanying the rotation of the intake cam shaft 51. 5, and is operated with a valve opening displacement amount as shown by a curve α in the characteristic diagram of FIG. 5, and a time point ta earlier than the top dead center TDCo in the exhaust stroke.
The transition from the valve-closed state to the valve-opened state is started at, and after the valve-opened state that takes the maximum valve-opening displacement, the valve-opened state is closed from the valve-opened state at time td later than the bottom dead center BDCi in the next suction stroke The transition to is completed. On the other hand, each of the pair of exhaust valves 23 follows the rotation of the pair of exhaust-side cam portions 63 accompanying the rotation of the exhaust-side cam shaft 52 as shown in FIG.
In the explosion stroke, the valve shifts from the closed state to the open state at a point earlier than the bottom dead center BDCc, and then the maximum opening state is started. After passing through the valve-opening state that takes the valve displacement amount, the valve is in the valve-opening state at time ta, and the transition from the valve-opening state to the valve-closing state is completed at time tc later than TDCe in the next exhaust stroke. It is assumed. Thereby, the overlap period TB in which the intake valve 21 and the pair of exhaust valves 23 are both opened.
Is set as a relatively long period from the time point ta to the time point tc.

On the other hand, the intake valve 20 is driven by the rotation of the intake cam portion 60 accompanying the rotation of the intake cam shaft 51.
The operation is performed with the valve opening displacement amount as shown by the curve γ in the characteristic diagram of FIG. 5, and the time tb is later than the time ta and earlier than the top dead center TDCe in the exhaust stroke.
At the time of te after the time td, which is later than the bottom dead center BDCi in the next suction stroke, through the valve opening state where the maximum valve opening displacement amount is obtained. The transition from the state to the closed state is completed. That is, the time point tb at which the intake valve 20 starts to shift from the closed state to the open state and the time point te at which the intake valve 20 completes the transition from the open state to the closed state are determined by the intake air, respectively. The time point ta at which the valve 21 starts the transition from the closed state to the open state, and the intake valve 2 thereafter.
1 is a time point td when the transition from the open state to the closed state is completed.
The intake cam portion 6 disposed on the intake camshaft 51 in comparison with
This is delayed by a time corresponding to the mutual rotational phase difference between 0 and the intake side cam portion 61. Thereby, the overlap period TA in which the intake valve 20 and the pair of exhaust valves 23 are both opened is the overlap period TB in which the intake valve 21 and the pair of exhaust valves 23 are both opened.
It is set as a shorter period, that is, a relatively short period from time tb to time tc included in the overlap period TB in which the intake valve 21 and the pair of exhaust valves 23 are both opened. The operation of the fuel injection valve 38 provided in the individual passage 35 is controlled so as to perform the fuel injection during the overlap period TA in which the intake valve 20 and the pair of exhaust valves 23 are both opened. .

As described above, when the piston member 59 is moved along the intake camshaft 51 against the urging force of the coil spring 58 by the action of the operating hydraulic pressure from the hydraulic circuit 49, the intake air Between the side camshaft 51 and the exhaust side camshaft 52, a rotation phase of the intake side camshaft 51 causes a mutual rotation phase change that is on the leading side with respect to the rotation of the exhaust side camshaft 52. Thereby, a pair of intake valves 20 and 21 provided for each cylinder 6 and a pair of exhaust valves 2 are provided.
3, an overlap period as indicated by TB in the characteristic diagram of FIG. 5, in which the intake valve 21 and the pair of exhaust valves 23 are both opened, and the intake valve 20 and the pair of exhaust valves 23. Are both opened, the overlap period as indicated by TA in the characteristic diagram of FIG. 5 is lengthened.

The hydraulic circuit 49 is controlled by a control block 50. The control block 50 includes a detection output signal Sn indicating an engine speed obtained from an engine speed sensor 65 and a crank output from a crank angle sensor 66. The detection output signal Sc indicating the rotation angle, the detection output signal Sa indicating the intake air flow rate obtained from the air flow sensor 26, and the detection output signal St indicating the throttle opening obtained from the throttle opening sensor 27A, etc. Various detection output signals indicating the operation state are supplied. Then, the control block 50 controls the control signal Co based on the supplied various detection output signals.
Is supplied to the hydraulic circuit unit 49, and the supply state of the operating oil pressure to the piston member 59 in the variable valve timing mechanism 45 of the hydraulic circuit unit 49 is controlled in accordance with the operation state of the engine body 1.

Under the control of the control signal Co from the control block 50, for example, when the engine body 1 is in a relatively low speed and low load operation state, the hydraulic circuit section 49 controls the piston member in the variable valve timing mechanism 45. In this state, the operating oil pressure is not applied to the piston member 59 of the variable valve timing mechanism 45 when the engine main body 1 is in a relatively high speed or high load operation state. Therefore, a pair of intake valves 20 and 2 provided for each cylinder 6
1 and the pair of exhaust valves 23 may be in a state where the engine main body 1 is in a relatively high-speed or high-load operation state, and the mechanical supercharger 31 is in a supercharging operation state and a knocking phenomenon is likely to occur. , The intake valve 21 and the pair of exhaust valves 23
In the characteristic diagram of FIG.
, And the intake valve 20 and the pair of exhaust valves 23 are both opened.
Each of the overlap periods indicated by TA in the characteristic diagram of FIG. 5 is lengthened.

In such a case, in particular, the intake port 8 connected to the individual passage 36 in which the fuel injection valve 38 is not provided is provided.
The intake valve 21 that opens and closes the opening to the cylinder 6 at the downstream end of the valve and the pair of exhaust valves 23 are both opened, and the overlap period as indicated by TB in the characteristic diagram of FIG. Thereby, scavenging of the post-combustion residual gas is performed favorably in each cylinder 6, whereby the temperature rise in each cylinder 6 is suppressed,
The occurrence of the knocking phenomenon is effectively suppressed. At the same time, the intake valve 20 for opening and closing the opening to the cylinder 6 at the downstream end of the intake port 7 connected to the individual passage 35 provided with the fuel injection valve 38 and the pair of exhaust valves 23 are both opened. The overlap period as indicated by TA in the characteristic diagram of FIG.
The intake valve 21 and the pair of exhaust valves 23 are shorter than the overlap period in which both are opened, and the fuel injection by the fuel injector 38 is performed by the intake valve 20 and the pair of exhaust valves 23. Is performed during the overlap period in which both the valves are opened, so that the fuel supplied to each cylinder 6 blows from the intake valve 20 side to the pair of exhaust valves 23, and the fuel exhaust manifold 13
In the individual passage 14 is suppressed. Further, since the intake valve 21 on the intake port 8 side is closed earlier than the intake valve 20 on the intake port 7 side, the fuel supplied through the intake valve 20 to each cylinder 6 is blown back to the intake port 8 side. The occurrence of the situation that occurs is also suppressed.

[0030]

In the above example, each cylinder 6
In contrast, two first and second individual intake passages 39 and 40 including intake ports 7 and 8 whose opening and closing are controlled by intake valves 20 and 21, respectively, are provided.
The individual intake passages 39 and 40 form a cylinder-specific intake passage portion. However, in the intake device of the engine with a mechanical supercharger according to the present invention, three or more individual intake passages are provided for each cylinder. A passage may be provided, and the three or more individual intake passages may form a cylinder-specific intake passage portion. In such a case, one of the three or more individual intake passages serves as a fuel supply passage for guiding the fuel from the fuel injection valve to the cylinder, and the intake air corresponding to the individual intake passage serving as the fuel supply passage. The point in time when the transition from the valve closing state to the valve opening state is started and the point in time when the transition from the valve opening state to the valve closing state is completed are changed from the valve closing state of the intake valves corresponding to the other individual intake passages. The time is assumed to be later than the time when the shift to the open state is started and the time after the shift from the open state to the closed state is completed.

Further, in the above-described example, regardless of the operating state of the engine body 1, the intake valve 20
Starts the transition from the closed state to the open state, and the time when the intake valve 20 completes the transition from the open state to the closed state, respectively, when the intake valve 21 is closed from the closed state. The time when the shift to the open state is started and the time when the intake valve 21 thereafter completes the shift from the open state to the closed state are delayed. The overlap period during which the valve 23 and the valve 23 are both opened is:
The intake valve 21 and the pair of exhaust valves 23 are set to have a period shorter than the overlap period in which both the valves are opened. However, in the intake device of the engine with a mechanical supercharger according to the present invention, Only when the engine body 1 is in a predetermined operating state, for example, a high-load operating state.
0 starts the transition from the closed state to the open state and the time when the intake valve 20 completes the transition from the open state to the closed state, respectively, when the intake valve 21 is in the closed state. From the start to the open state, and the time after which the intake valve 21 completes the transition from the open state to the closed state. The overlap period during which the exhaust valve 23 and the exhaust valve 23 are both opened is:
The period may be shorter than the overlap period in which the intake valve 21 and the pair of exhaust valves 23 are both opened.

[0033]

As is apparent from the above description, according to the intake system for a mechanical supercharged engine according to the present invention, each of the plurality of cylinders provided in the engine body is connected to the common intake passage. The first individual intake passage only in the first individual intake passage of the first and second individual intake passages
Open and close to open and close the opening to the cylinder
The first intake valve selectively takes the state and the cylinder.
Overlap where the corresponding exhaust valve is both opened
Fuel supply means for performing fuel supply operation with respect to the cylinder is arranged in the period, at least the engine body a predetermined operating condition, for example, when in a high load operating state, in the intake stroke for each cylinder, a first The time when the intake valve starts to shift from the closed state to the open state is the second time.
A second intake valve that selectively takes an open state and a closed state to open and close the opening of the individual intake passage to the cylinder is later than the time when the transition from the closed state to the open state is started. And the time when the first intake valve completes the transition from the open state to the closed state after that is later than the time when the second intake valve completes the transition from the open state to the closed state. Therefore, at least when the engine body is in the high-load operation state, the overlap period in which the second intake valve and the exhaust valve corresponding to the cylinder are both opened in each cylinder is relatively long. And the fuel supply means arranged in the first individual intake passage.
The first period during which fuel is supplied to the cylinder .
Overlap period and the exhaust valve are both an open state corresponding to the intake valve and the cylinder are relatively short, this
As described above, the overlap period between the second intake valve and the exhaust valve is made relatively long, so that scavenging of each cylinder is performed favorably, and the temperature rise in each cylinder is suppressed. As a result, the occurrence of the knocking phenomenon is effectively suppressed, and the overlap period between the first intake valve and the exhaust valve is relatively shortened.
The amount of fuel blown out to the exhaust passage portion side caused by the fuel supplied to the cylinder by the fuel supply means disposed in the individual intake passages flowing from the first intake valve side to the exhaust valve side is suppressed. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an intake device of a mechanical supercharged engine according to the present invention together with an engine to which the intake device is applied.

FIG. 2 is an example of an intake device for a mechanical supercharged engine according to the present invention and a partial cross-sectional view of an engine to which the intake device is applied.

FIG. 3 is a cross-sectional view for explaining the structure of an example of an intake device of the engine with a mechanical supercharger according to the present invention.

FIG. 4 is a plan view including a partial cross-sectional view showing a part of an example of an intake device of an engine with a mechanical supercharger according to the present invention.

FIG. 5 is a characteristic diagram used to explain the operation of an example of the intake device of the engine with a mechanical supercharger according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine main body 6 Cylinder 7 Intake port 8 Intake port 9 Branch exhaust port 10 Common intake passage part 20 Intake valve 21 Intake valve 23 Exhaust valve 31 Mechanical supercharger 35 Individual passage 36 Individual passage 38 Fuel injection valve 39 Individual intake passage 40 Individual intake passage 45 Variable valve timing mechanism 49 Hydraulic circuit unit 50 Control block 51 Intake side camshaft 52 Exhaust side camshaft 60 Intake side cam unit 61 Intake side cam unit 63 Exhaust side cam unit

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI F02D 43/00 301 F02D 43/00 301J 301Z F02M 69/00 360 F02M 69/00 360B (56) (JP, A) JP-A-63-297728 (JP, A) JP-A-3-88907 (JP, A) JP-A-3-156123 (JP, A) JP-A-3-202602 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 13/00-45/00

Claims (1)

(57) [Claims] 1. A common intake passage portion in which a mechanical supercharger driven by an engine output is disposed, and a plurality of cylinders in an engine body in which a plurality of cylinders are formed are provided corresponding to each of the plurality of cylinders. Includes a first and a second individual intake passage connecting a corresponding cylinder and the common intake passage portion, and supplies fuel to the first individual intake passage for the corresponding cylinder. A first intake valve for selectively opening and closing a valve to open and close an opening of the first individual intake passage for the corresponding cylinder; A second intake valve for selectively opening and closing a valve opening state and a valve closing state to open and close an opening of the second individual intake passage with respect to the corresponding cylinder; and the first and second intake valves. Drive When the engine main body is in a predetermined operating state, the time when the first intake valve starts shifting from the closed state to the open state in the suction stroke of the corresponding cylinder is referred to as the second time. The time when the first intake valve completes the transition from the open state to the closed state after the time at which the intake valve starts to transition from the closed state to the open state is referred to as and slow ones and constitute the intake valve driving control means from completion timing of the transition from the second intake valve is opened to the closed state, with the said fuel supply means, the first intake valve and the corresponding Do
Exhaust valve arranged in individual exhaust passage connected to cylinder
During the overlap period when both are open
To supply fuel to the corresponding cylinder.
An intake device for an engine with a mechanical supercharger , characterized in that: